Optimizing Radiosurgery for Trigeminal Neuralgia: Impact of Radiation Dose and Anatomic Target on Patient Outcomes.

OBJECTIVE: Radiosurgery is an increasingly popular treatment for trigeminal neuralgia (TN); however, several treatment variables require further study. This meta-analysis was conducted to clarify ambiguity in the literature and optimize treatment parameters. METHODS: A random-effects proportions meta-analysis using subgroup analysis and meta-regression investigated the association of prescription dose and anatomic target on outcomes in patients with typical TN. The PRISMA guidelines were used. Radiation doses used ranged from 70 to 90 Gy and the anatomic targets were either the root entry zone or a more distal nerve location. Outcome measures were pain at last follow-up and the development of bothersome numbness. RESULTS: Increasing radiation prescription dose was associated with improved outcomes across all analyzed doses (P < 0.001). Patients treated at a distal trigeminal nerve target had better pain control compared with a root entry zone target (P < 0.001). Despite a higher median dose, a distal target was independently associated with improved pain control. There were similar rates of bothersome numbness across radiation doses and both treatment targets. CONCLUSIONS: Higher radiation dose was associated with superior pain control without increasing bothersome numbness. Independent of dose, the distal target was also associated with improved pain control. Bothersome numbness was not related to dose or target.